J. White calculates why Apollo craft could not have survived passage through the VABs

originally posted by: choos'
a reply to: FoosM

have you checked his numbers??

Everyone here seems hung up on "the math." If I make the statement, "2+2=4, so elephants are all fish." there is nothing at all wrong with the math, but the statement is still nonsense. The radiation this guy is concentrating on is almost all Beta radiation, which can be totally blocked my a couple millimeters of aluminum. If a lot of it hits you, its really bad but a beer can will shield you. Alpha radiation is even less penetrating. A piece of paper will block it. There are almost no gamma rays in the VAB which is good, since they are the real bad boys. The "math" that is ignored but important is the equation E=hv.

The worse thing about moon-walking deniers is that some people may believe them, and thus not bask in the glory that was Nome and realize that man did walk on the moon, twelve of them walked and worked there, and they did this only 44 years ago. There are thousands of people around you who watched and marveled at the grand achievement. To not have that knowledge, to think otherwise, diminishes the wonder of that pioneering effort.

Man did go to the moon, and as I've often mentioned in posts, everyone should have the experience of meeting or talking to at least one of those 12 men while you can - for how many thousands of generations of humans will not be able to thank one of the these immortals in person or on the phone.

a reply to: F4guy:

Everyone here seems hung up on "the math." If I make the statement, "2+2=4, so elephants are all fish." there is nothing at all wrong with the math, but the statement is still nonsense. The radiation this guy is concentrating on is almost all Beta radiation, which can be totally blocked my a couple millimeters of aluminum.

Please show us where the belts are just simply made up of Beta radiation

edit to add:
Let me clarify... if space-ships are already made up of aluminum, and other forms of metal, why do you need shielding?

originally posted by: Expat888
*fires up cigar.. mixes drink..* waits on phage to show up .. this should be a good show ..

Why? does he pole dance in the moonlight?

If so, Ill load up instagram.

a reply to: Aleister:

The worse thing about moon-walking deniers is that some people may believe them, and thus not bask in the glory that was Nome and realize that man did walk on the moon, twelve of them walked and worked there, and they did this only 44 years ago. There are thousands of people around you who watched and marveled at the grand achievement. To not have that knowledge, to think otherwise, diminishes the wonder of that pioneering effort.

And because of this, you are a shining example why people
do not check NASA's math on such subjects. Why we need to
get it from some youtube dude out in Australia.

originally posted by: FoosM

And because of this, you are a shining example why people
do not check NASA's math on such subjects. Why we need to
get it from some youtube dude out in Australia.

funny thing to say considering you havent checked Jarrahs numbers yourself.. kettle calling the pot black??

it looks like Jarrah is off by a factor of several thousand

originally posted by: FoosM
a reply to: Aleister:

The worse thing about moon-walking deniers is that some people may believe them, and thus not bask in the glory that was Nome and realize that man did walk on the moon, twelve of them walked and worked there, and they did this only 44 years ago. There are thousands of people around you who watched and marveled at the grand achievement. To not have that knowledge, to think otherwise, diminishes the wonder of that pioneering effort.

And because of this, you are a shining example why people
do not check NASA's math on such subjects. Why we need to
get it from some youtube dude out in Australia.

If I could do math I'd prove why time and gravity are the same thing, but I don't. And yes, humans went to the moon. Six times, and a few more with people going around It. It's almost legendary now, so like I said, meet or talk to at least one of the men who were there before we can't anymore. I've talked to almost all of them and met three (counting coup on moon walkers).

originally posted by: choos

originally posted by: FoosM
a reply to: choos

Engineers and scientists have been working with old data for their satellites.
They have complained to NASA to update the VAB charts. That was supposed to have
happen a few years ago, I doubt this is the case.

Engineers and Scientists also dont have to worry about sending lifeforms through
the belts.

Big question is, where is NASA's calculations for Apollo's traversal through the VABs?

update the charts?? so you mean to date all satellites are fake?? Jarrah makes it seem impossible to shield against the VAB radiation? so if we take what he says of 60,000-4,000,000 rads per hour i guess satellites will just fail after a few days

Yes, update the charts:

The need:

• Specification of energetic protons is the highest priority of satellite design community
• AP-8 has well-known under-prediction problems at higher proton energies (> 50 MeV) and
in the slot region
• Inner zone protons are poorly measured ,
–HEO-1/Dosimeter (1994 – current) – very little inner zone coverage
–HEO-3/Dosimeter (1997 – current) – little inner zone coverage and contamination issues – ICO/Dosimeter (2001 – current) – only outside of inner zone coverage –CRRES/PROTEL (1990-1991) – covers the complete inner zone but has contamination

lws-set.gsfc.nasa.gov...

originally posted by: choos

originally posted by: FoosM

And because of this, you are a shining example why people
do not check NASA's math on such subjects. Why we need to
get it from some youtube dude out in Australia.

funny thing to say considering you havent checked Jarrahs numbers yourself.. kettle calling the pot black??

it looks like Jarrah is off by a factor of several thousand

Please show me NASA's math.

originally posted by: FoosM

Yes, update the charts:

so satellites and probes that need to go in or work within the VAB dont exist since they have been using numbers extremely too low??

Please show me NASA's math.

you keep ignoring my question?? are you vouching for Jarrahs calculations?? are you believing Jarrahs calculation without checking it yourself??

if i told you his calculations are off by several thousand i guess you would dispute my claim?

also Jarrah uses sources that have estimated shielding required..

how else does jarrah know that 1Mev cant penetrate 0.545gm/cm^2 of aluminium??

so, again.. have you checked Jarrahs numbers?

Whilst I am by no means a mathematician nor a physicist, I simply cannot take Jarrah White seriously. First the intro to the video... James Bond? Really? Calling yourself the "Grandson of the Apollo Moon Hoax Theory"? What does that even mean? And trying to convince me of some serious "facts" whilst sitting in - what can only be - his grandma's armchair? Yeah...no.

But let's ignore the personal shortfalls, and consider the fact that he starts the video with a quote (e-mail) from Professor James Alfred Van Allen that states:

However, the outbound and inbound trajectories of the Apollo spacecraft cut through the outer portions of the inner belt and because of their high speed spent only about 15 minutes in traversing the region and less than 2 hours in traversing the much less penetrating radiation in the outer radiation belt. The resulting radiation exposure for the round trip was less than 1% of the fatal dosage - a very minor risk among the far greater risks of such flights. I made such estimate in the early 1960s and so informed NASA engineers who were planning the Apollo flights. These estimates are still reliable.

The recent Fox TV show, which I saw, is an ingenious and entertaining assemblage of nonsense. The claim that radiation exposure during the Apollo missions would have been fatal to the astronauts is only one example of such nonsense.

Mr White wants to disagree with Van Allen about the Van Allen belts? Really? REALLY?! It's laughable. You want to argue facts about a topic with (probably) the most knowledgeable person on the topic? Van Allen had more than 70 years experience in the field... What is White's credentials?

And let's hear from some other subject matter experts with actual credentials behind their names:

"Thanks also for the URL to the youtube video. The speaker is very ignorant of basic physics, and contradicts himself a few times (in the sense of Physics)."

- Dr Karl Kruszelnicki, Julius Sumner Miller Fellow, The Science Foundation for Physics, School of Physics, The University of Sydney

"Guys like this idiot Jarrah White are a dime-a-dozen and no matter what we say, they are not going to change their mind."

- Mr Stephen Clemmons, Apollo 1 Pad Technician (North American Aviation), Present on Level 7 during AS-204 fire, 27 JAN 67

"...all space missions carry devices to measure the radiation doses. Astronauts should not be outside of a space craft if there were an SPE. They should be shielded inside the space craft. Hence, radiation exposures for Apollo missions would be very small. Hence, I believe that radiation exposures from Apollo missions were very small, unless astronauts stayed outside during an SPE about which they would have been informed..."

- Richard B. Setlow, Senior Biophysicist Emeritus, Member of the National Academy of Sciences, Brookhaven National Laboratory

And so on

Jarrah makes some pretty wild assumptions in his calculations as many have already pointed out, and very often take option C above option A just to make sure he creates a worst case scenario...

Bottom line is - I am by no means an expert on the matter, but I still have the common sense to know what I can accept as fact and what not. As W.C. Fields said: “If you can't dazzle them with brilliance, baffle them with bull[snip].” And Jarrah White is quite an expert on the latter, if nothing else.

Come on, all these posts and bickering and nobody has bothered to point out Jarrah's glaring, indisputable, massive, UTTERLY ELEMENTARY screw-up?

What's wrong with this picture? (Apart from the floral arrangements, and the fact that the symbol for grays is Gy, not Gr!)



How about the fact that 1 gray is 1 joule PER kg, not 1 joule.kilogram.

Jarrah multiplied when he should have divided. Which is kind of like saying that if it takes you 12 hours to drive 500 miles, your average speed is 6,000 mph. Utterly boneheaded, in other words.

Even if the rest of his figures were right (which I am pretty sure they are not, but I haven't been through them all yet), that immediately makes his numbers too big by a factor of 75², or 5,625!



Now, time to hand in your homework, Jarrah. Oh dear.



You'd think he might have performed some kind of sanity check and noticed that his claimed value would provide a lethal dose in less than 30 seconds, or enough to kill a satellite in 20 minutes. His figures are more akin to flying through an atom bomb explosion!

This isn't some advanced mathematical operation here. It's multiplying instead of dividing. That's just about the simplest, most elementary error in the book.

He clearly has a major mental block when it comes to maths (this is hardly his first arithmetic fail) and yet he thinks he can outsmart actual scientists. It's totally comical.

Good old Jarrah. They don't call him the Blunder from Down Under for nothing.

originally posted by: Rob48
Come on, all these posts and bickering and nobody has bothered to point out Jarrah's glaring, indisputable, massive, UTTERLY ELEMENTARY screw-up?

What's wrong with this picture? (Apart from the floral arrangements, and the fact that the symbol for grays is Gy, not Gr!)

[snip]

Great, well please continue, I would like to see what numbers you will come up with.

originally posted by: FoosM

originally posted by: Rob48
Come on, all these posts and bickering and nobody has bothered to point out Jarrah's glaring, indisputable, massive, UTTERLY ELEMENTARY screw-up?

What's wrong with this picture? (Apart from the floral arrangements, and the fact that the symbol for grays is Gy, not Gr!)

[snip]

Great, well please continue, I would like to see what numbers you will come up with.

Oh, I will.

In the meantime, here's a number to chew on.

The estimated radiation dose right at the hypocentre of the Hiroshima explosion was 240 Gy.

According to Jarrah, the Apollo astronauts received 15 times that dose every hour. Or the equivalent of an atomic bomb every four minutes.

He actually wrote this figure, 3,672 Gy/hr, on his video caption and it didn't give him pause for thought? Doesn't that tell you he hasn't a clue about radiation?

originally posted by: Rob48

originally posted by: FoosM

originally posted by: Rob48
Come on, all these posts and bickering and nobody has bothered to point out Jarrah's glaring, indisputable, massive, UTTERLY ELEMENTARY screw-up?

What's wrong with this picture? (Apart from the floral arrangements, and the fact that the symbol for grays is Gy, not Gr!)

[snip]

Great, well please continue, I would like to see what numbers you will come up with.

Oh, I will.

In the meantime, here's a number to chew on.

The estimated radiation dose right at the hypocentre of the Hiroshima explosion was 240 Gy.

According to Jarrah, the Apollo astronauts received 15 times that dose every hour. Or the equivalent of an atomic bomb every four minutes.

He actually wrote this figure, 3,672 Gy/hr, on his video caption and it didn't give him pause for thought? Doesn't that tell you he hasn't a clue about radiation?

I see, but somebody must of already figured it out, how many Gy's, RADs or Sieverts does NASA say is in the Proton and Electron belts? It would be nice to see what calculation you make vs Jarrah vs NASA.

a reply to: FoosM

Well, before Apollo 8 it was predicted that traversing the VAB would expose the astronauts to about 1 mGy (0.001 Gy). The actual measured exposure on that mission was 1.6 mGy.

Robert Braeunig has conducted some pretty detailed calculations here which show that even without any shielding at all, the Apollo 11 crew would have received about 114 mGy on the way to the moon. A fatal whole body dose would be of the order of 4 Gy, or 4000 mGy.

So you can see that (from a radiation point of view at least), the Apollo 11 crew could actually have travelled outside the command module all the way through the Van Allen belts. (The crew of Apollo 14 would have been in trouble if they were outside, though!)

I'll crunch the numbers as soon as I get the chance. I have a feeling Jarrah has made more than one error here, as even if you take into account his multiplication/division confusion, his numbers still look way too high.

originally posted by: FoosM

originally posted by: Rob48

originally posted by: FoosM

originally posted by: Rob48
Come on, all these posts and bickering and nobody has bothered to point out Jarrah's glaring, indisputable, massive, UTTERLY ELEMENTARY screw-up?

What's wrong with this picture? (Apart from the floral arrangements, and the fact that the symbol for grays is Gy, not Gr!)

[snip]

Great, well please continue, I would like to see what numbers you will come up with.

Oh, I will.

In the meantime, here's a number to chew on.

The estimated radiation dose right at the hypocentre of the Hiroshima explosion was 240 Gy.

According to Jarrah, the Apollo astronauts received 15 times that dose every hour. Or the equivalent of an atomic bomb every four minutes.

He actually wrote this figure, 3,672 Gy/hr, on his video caption and it didn't give him pause for thought? Doesn't that tell you he hasn't a clue about radiation?

I see, but somebody must of already figured it out, how many Gy's, RADs or Sieverts does NASA say is in the Proton and Electron belts? It would be nice to see what calculation you make vs Jarrah vs NASA.

have you even watched jarrahs video???

in his video he directly shows you what other people have calculated.. go read the apollo 11 lunar trajectory that Jarrah refers too..

having said that..

mistake number 2 that jarrahs makes..

he uses the wrong chart/illustration!!

that illustration that jarrah uses to work out the particles per square metre is wrong.. notice how he cuts out the bottom part of the illustration?


if you had bothered to check his sources you would have found that that was for particles with greater than 0.5MeV.. heres the FULL chart/illustration


that might seem correct for you??

what about the chart below that?


particles with greater than 1MeV

"so what" you say?? the second chart has less flux..

In general, flux and energy vary inversely. That means the higher the energy, the lower the flux. So if we look at the low-energy particles, we may find an enormous flux.
www.clavius.org...

oh look, more flux = less energy.. the less flux = more energy..
or more simply, the more particle density the less energy each particle has, the more particle density the less energy each particle carries.

lets see at about 5 earth radii 0.5MeV would be about 2x10^6 flux
and about 5 earth radii 1MeV is between 10^5 and 10^4..

about 5% of the amount.. and thats only 1MeV.. 10 MeV which Jarrah uses, would have even less particles..

there even a chart for 100MeV but the highest that goes is 10^3 and they spend less than 5minutes traversing that..

mistake number 3:

Jarrah's calculation is assuming there IS NO SHIELD..
and he adds on the Bremsstrahlung effect????? if he calculates the radiation without a shield why does he add on the Bremsstrahlung radiation also when there is no shield???

so far these are all the mistakes ive worked out and im not even close to an expert..

you, FoosM, have posted a hoax video, and as shown by GemWolf he is a known hoaxer..
the real question is now, did you knowingly post a hoax video?? which is against the T&C..
or are you just trying to gain more views for your.. i mean Jarrahs video??

perhaps you didnt know, in which case, why are you believing some guy with no credentials, blindly, without checking their numbers? you have fallen for his charlatan ways..

to repeat GemWolf:
"As W.C. Fields said: “If you can't dazzle them with brilliance, baffle them with bull[snip].” And Jarrah White is quite an expert on the latter, if nothing else."

originally posted by: FoosM

originally posted by: Rob48
Come on, all these posts and bickering and nobody has bothered to point out Jarrah's glaring, indisputable, massive, UTTERLY ELEMENTARY screw-up?

What's wrong with this picture? (Apart from the floral arrangements, and the fact that the symbol for grays is Gy, not Gr!)

[snip]

Great, well please continue, I would like to see what numbers you will come up with.

As promised.

WARNING. LONG POST. LOTS OF MATHS. PROCEED WITH CAUTION

OK, I've been through the maths. And I warn you: it ain't pretty. In summary, he ends up off by a factor of 70,000, and then it deteriorates from there.

Let's begin.

After the usual long waffly preamble, at 8:12 in the video, Jarrah says "But really, all one needs to prove one's case is basic mathematics". You said it, mate.


From around 9:00 he shows Braeunig's chart. OK so, he doesn't get any of the numbers wrong, but he doesn't grasp the significance of it showing electrons with energies "greater than 0.5 MeV".

At 10:00 he asks, "But just how high is greater than 0.5 MeV?"

The answer he goes with is up to 10 MeV, but he gives no clue of the frequency distribution. If the vast majority are around 0.5-1 MeV with only a very few up to 10 MeV then this is pretty meaningless. You don't use the flux of >0.5 MeV electrons as the flux of 10 MeV electrons! There will be orders of magnitude fewer.

At 13:14 he claims that the heat shield areal density is 7.59 g/cm^2, but the rest of the hull is 1.98 g/cm^2.

Then in the very next slide he is using a value of 3.33 g/cm^2. Where did that come from? Never mind, I'll use his figure.

---------------------------------------------

Now we get onto the actual maths part...


At 13:43 he is taking the flux of 10^6 electrons/cm^2/s and pretending that all of these electrons are 10 MeV. But remember, the original chart showed that this flux applies to electrons with energies >0.5 MeV, or one twentieth of the value he uses!


STEP 1

Convert to electrons per square metre per hour.

Yes, he gets this right.
3.6 x 10^13 electrons/m^2/h


STEP 2

Multiply by the front surface area of an adult human.

Again, no problems here, although he is assuming that the person is standing up and presenting the maximum surface area to the electron flux at all times. But that is a minor quibble.
3.06 x 10^13 electrons/h

However, that assumes that all of those electrons actually reach the astronaut, which they don't, as I show next...


STEP 3

Find out how much energy is absorbed every hour.

Woah! Stop right there. Here is where the errors start cropping up.

Error 1: as I said before, he is taking the AVERAGE electron energy as 10 MeV, when this is actually the TOP END of the quoted range. Even if you take a simple average of the range of 0.5 - 10 MeV then you only get 5.25 MeV, and in fact the vast majority of electrons have energies below 5 MeV so even this would be too high.

Error 2: he is totally ignoring the shielding! Even if, as he claims, the average shielding is only 3.33 g/cm^2, this still stops electrons up to 6.1 MeV (as he says at 13:27 in the video). And it will also proportionally reduce the energy of the higher energy electrons. A 10 MeV electron that passes through this shielding will have its energy reduced by more than half.

Now, sorting out this mess isn't straightforward, so I am going to make some gross assumptions that give Jarrah the benefit of the doubt. Let's assume that there is a totally even probability distribution of electrons from 0.5 MeV right up to 10 MeV. (In fact, the distribution will be skewed towards the lower end.)

We now strip out all the electrons below 6.1 MeV, as they are blocked by the shielding, and reduce the energy of all those above this level by the same amount.

So our total electron flux is now:

3.06 x 10^13 electrons/h x (10-6.1)/(10-0.5) = 1.26 x 10^13 electrons/h

And they now have energies between 0 MeV and 3.9 MeV, so let's call the average 2 MeV.

So, Jarrah's calculation for the energy absorbed per hour should be:

1.26 x 10^13 electrons/h x 2 MeV/electron

= 2.52 x 10^13 MeV/h

This is about 12 times lower than Jarrah's figure already.

(I'm not even going to go into his incorrect units and weird notation in this frame, or why he bothered converting down to eV!)


STEP 4

Convert to joules

He gets this part right, although the value he plugs in is, as I say, much too high. Using my figures you get:

2.52 x 10^13 MeV/h x 1.6 x 10^-13 J/MeV

= 4.03 J/h


STEP 5

COnvert to grays

"Now here's where the gloves come off," says Jarrah. Actually I think he must have been wearing boxing gloves when he did this calculation. As I pointed out before, this is his biggest single error. He multiplies the absorbed energy by the astronaut's mass, instead of dividing! (Remember, he has already multiplied it up by the astronaut's surface area, so this is already the full-body dose.)

What Jarrah should have done here is:

4.03 J/h / 75kg

= 0.053 Gy/h

Yes, that's about 0.05 grays per hour, not 3,672. He is now off by a factor of almost 70,000, and yet I am still giving him the benefit of the doubt by overestimating the electron energies!

He now converts to rad, and still doesn't notice the ludicrous figures he has.

What he should have here is:

0.053 Gy/h x 100 rad/Gy

= 5.3 rad/h

Doubling up as Jarrah does for the regions with higher electron flux gives 10.6 rad/h.

Jarrah even says here "Keep in mind that death is likely after 500 rad in any short time", and yet he doesn't make any comment on the fact that his numbers are a thousand times higher!



Next he calculates the Bremsstrahlung ("braking radiation") from the electrons that are being stopped by the shielding (which he ignored!)

His calculation also again uses 10 MeV, when a fairer (but still likely MUCH too high) value would be 5 MeV.

So it should be:

f = 7 x 10^-4/MeV x 13 x 5 MeV

= 0.046

Energy of generated photons = 0.046 x 5 MeV = 0.23 MeV.

Leading to:


STEP 6

Convert X-ray energy to joules

0.23 MeV x 1.6 x 10^-13 J/Mev = 3.68 x 10^-14 J.


CONTINUED IN NEXT POST... I've run up against the character limit

STEP 7

Convert electron flux to x-ray flux

Well, his first slide here has an error in it (3.6 x 10^6 should read 3.6 x 10^13) but let's ignore that.

Now, Jarrah is trying a bit of sneaky double-counting here, because he took the full energy of the electrons ignoring shielding, but now he is including the Bremsstrahlung radiation that you only get if there is shielding! Nice try.


STEP 8

Calculate energy absorbed

Using my numbers we get:

3.06 x 10^13 X-rays/h x 3.68 x 10^-14 J/X-ray = 1.13 J/h

and for the doubled region 2.25 J/h

He then repeats his error with multiplying instead of dividing and ends up with more stupid numbers for grays.


STEP 9

Convert from joules to grays

What he should get is

1.13 J/h / 75 kg = 0.015 Gy/h, and 0.03 Gy/h for the doubled region. Not 334 and 668 Gy/h. This time he's off by a factor of about 22,000!


STEP 10

Convert from grays to rads

Again, this now converts to 1.5 rad/h and 3 rad/h.


He then converts these to the figures for 1 MeV electrons, by dividing by 10^2 (or that is what he should do, but he actually bothers to repeat the calculations and then with no hint of understanding says "we find that the doses are reduced by a factor of about 100"! He simply doesn't grasp what he's done.)

I was using 5 MeV electrons, so I need to divide by 5^2 instead:

For 1 MeV electrons the figures should be 1.5/25 and 3/25 = 0.06 rad/h and 0.12 rad/h respectively.


He then multiplies by the time:

40 min in the lower density region = 0.06 rad/h x (2/3) h = 0.04 rad

20 min in the higher density region = 0.12 rad/h x (1/3) h = 0.04 rad ("What a coincidence!" says Jarrah )

Add them together and we get 0.08 rad. Not 445 rad as Jarrah has!

Or 0.16 rad for the two-way trip for 1 MeV electrons, and 16 rad for 10 MeV electrons.

He then takes an average of the two figures and gets 45,000 rad! I get (0.16 + 16) / 2 = 8.1 rad.




Now (around 18:50) he goes on a diversion into higher energy electrons, and decides that just because some electrons (in areas of the belts that were NEVER TRAVERSED by Apollo) have energies of up to 100 MeV, he is justified in upping his average even more, to >55 MeV!

This is just too silly for words.

And again he screws up all the calculations in the same manner and ends up with figures of 2.7 MILLION rads, or 27,000 Gy! This is now over 100 times the radiation dose you would have got if standing at ground zero in Hiroshima.

And still Jarrah thinks this is all kosher.



So, if anyone is still here after that little lot, the take-home from me using VERY rough figures is as follows:

Radiation from electrons in the belts:

5.3 rad/h for 40 min plus 10.6 rad/h for 20 min = 3.53 + 3.53 = 7.1 rad, or for a two-way trip 14.2 rad.

Radiation from X-rays:

0.16 rad for a two-way trip, ie negligible compared to the electron radiation.

Total is less than 15 rad, or 0.15 Gy.

The actual maximum recorded value for (Apollo 14) was less than one tenth of this value, as you would expect because in the first part I used Jarrah's own very high estimates for electron energies, and I also deliberately overstated the Bremsstrahlung energies. I could work out some much better estimates using the actual frequency distribution, but honestly I have already spent much too long on this.


QED. You have not been billed for this work. Hopefully, FoosM, you now understand that Jarrah is not to be trusted with numbers. Quite frankly I wouldn't even trust him to give me the correct change for my burger.

originally posted by: Rob48

At 13:14 he claims that the heat shield areal density is 7.59 g/cm^2, but the rest of the hull is 1.98 g/cm^2.

Then in the very next slide he is using a value of 3.33 g/cm^2. Where did that come from? Never mind, I'll use his figure.

great post, and to add to this part he is only calculating the outer hull, completely ignores the inner pressure hull and insulation..

but then again his calculations dont even take into account shielding.